A vena cava filter delivery system and its control method

Abstract

This invention provides a vena cava filter delivery system and its control method. The vena cava filter delivery system includes: a delivery sheath, a sealing assembly, a pushing assembly, and a filter. The sealing assembly is disposed at the proximal end of the delivery sheath, and the filter is housed within the lumen of the delivery sheath. The pushing assembly extends continuously into the lumen of the sealing assembly and the delivery sheath and drives the filter to move relative to the delivery sheath. A limiting member is disposed at the distal end of the pushing assembly. The filter is constructed with multiple sets of support structures evenly spaced circumferentially and increasing in length along a first direction. The support structures are held in a retracted state against the radial direction between the delivery sheath and the limiting member. The retracted support structures are moved within the lumen of the delivery sheath along the first direction or in a second direction opposite to the first direction by the pushing action of the limiting member. This application achieves precise release of the filter into the appropriate position in the inferior vena cava, reducing the risk of thrombus dislodgement or filter displacement.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a vena cava filter delivery system and its control method. Background Technology

[0002] For patients at high risk of pulmonary embolism, implanting a filter in the inferior vena cava to capture thrombi can effectively prevent thrombus dislodgement and entry into the lungs, thereby reducing the incidence of pulmonary embolism. However, in existing inferior vena cava filter delivery devices, if the filter's position deviates during deployment, it is usually impossible to readjust its position. This may result in the filter not being precisely deployed to the appropriate location in the inferior vena cava, increasing the risk of thrombus dislodgement or filter displacement, and reducing the success rate of the procedure. Summary of the Invention

[0003] The purpose of this invention is to provide a vena cava filter delivery system and its control method, especially to achieve precise release of the filter at the appropriate location in the inferior vena cava, thereby reducing the risk of thrombus dislodgement or filter displacement.

[0004] The present invention provides a vena cava filter delivery system, comprising: a delivery sheath, a sealing assembly, a pushing assembly, and a filter;

[0005] The sealing assembly is disposed at the proximal end of the delivery sheath, the filter is housed in the inner cavity of the delivery sheath, and the pushing assembly extends continuously into the inner cavity of the sealing assembly and the delivery sheath and drives the filter to move relative to the delivery sheath.

[0006] The remote end of the push component is configured with a limiting device;

[0007] The filter is constructed with multiple sets of support structures that are equally spaced along the circumference and whose length increases along the first direction.

[0008] The support structure is held in a retracted state between the delivery sheath and the limiting member in the radial direction. The retracted support structure is moved in the inner cavity of the delivery sheath along the first direction or in a second direction opposite to the first direction by the pushing action of the limiting member.

[0009] According to the present invention, in some embodiments, the filter includes: a head end that engages with the opening of the delivery sheath, and a plurality of the support structures extending from the end of the head end along the first direction.

[0010] According to the present invention, in some embodiments, the support structure includes: a plurality of first support arms, second support arms and third support arms whose lengths increase along a first direction;

[0011] The length of the first support arm is less than the length of the second support arm, and the length of the second support arm is less than the length of the third support arm.

[0012] According to the present invention, in some embodiments, the outer part of the head end is a conical structure and forms a through guide wire cavity, the center of the head end is hollowed out to form a hook-shaped structure, and the head end is constructed to have a protrusion that fits into the opening of the delivery sheath.

[0013] According to the present invention, in some embodiments, the limiting member at least partially radially abuts against the third support arm in its retracted state and extends toward the first support arm.

[0014] According to the present invention, in some embodiments, the pushing assembly includes: an inner sheath extending continuously into the inner cavity of the sealing assembly and the delivery sheath, a limiting member sleeved on the distal outer side of the inner sheath, and a handle disposed on one end of the inner sheath extending out of the sealing assembly.

[0015] According to the present invention, in some embodiments, the first support arm includes: a first support portion and a second support portion extending continuously outward relative to the axis of the filter, and a third support portion connecting the second support portion and extending continuously inward relative to the axis of the filter.

[0016] According to the present invention, in some embodiments, the overall profile of the second support arm is arc-shaped, and the free end of the second support arm is provided with barbs that bend radially outward for anchoring on the inner wall of the blood vessel.

[0017] According to the present invention, in some embodiments, the overall outline of the third support arm is a linear structure, and the free end of the third support arm extends along the first direction to form an anchoring spike for anchoring on the inner wall of the blood vessel.

[0018] According to the present invention, in some embodiments, the angle at which the first support portion of the first support arm extends outward from the end of the head end is greater than the angle at which the second support arm extends outward from the end of the head end.

[0019] According to the present invention, in some embodiments, the sealing assembly includes: a multi-channel valve tube and a suction tube, the side of the multi-channel valve tube being configured to communicate with the suction tube, and a seal disposed at the proximal end of the multi-channel valve tube;

[0020] The inner sheath extends through the multi-channel valve tube along the second direction and extends to the delivery sheath tube, and the seal is used to seal the connection between the inner sheath tube and the proximal end of the multi-channel valve tube.

[0021] The present invention also provides a control method for a vena cava filter delivery system, applied to the above-mentioned vena cava filter delivery system, comprising the following steps:

[0022] S1. The air inside the delivery sheath is vented through the sealing assembly;

[0023] S2. Guide the delivery sheath along the guidewire to the target location in the inferior vena cava;

[0024] S3. The pushing component drives the limiting member to move along the second direction. Through the pushing action of the limiting member, the support structure in the retracted state moves along the second direction from the inner cavity of the conveying sheath to the outer cavity of the conveying sheath.

[0025] S4. After the filter moves from the inner cavity of the delivery sheath to the target position outside the inner cavity of the delivery sheath, the support structure switches from the retracted state to the extended state.

[0026] According to the present invention, in some embodiments, the pushing component drives the limiting member to move along a second direction, and the pushing action of the limiting member moves the retracted support structure along the second direction from the inner cavity of the delivery sheath to the outer cavity of the delivery sheath, including:

[0027] If the release position of the filter is deviated, the pushing component will drive the support structure to move along the first direction in the inner cavity of the delivery sheath before the set of support structures near the far end of the delivery sheath unfolds, so as to adjust the release position of the filter.

[0028] After the filter is adjusted to the appropriate release position, the push assembly drives the support structure to move along the second direction from inside the delivery sheath to outside the delivery sheath to the target position.

[0029] The vena cava filter delivery system and control method of the present invention have the following beneficial technical effects: During the gradual movement of the filter towards the target position, if the release position of the filter deviates, before a set of support structures near the distal end of the delivery sheath completely detaches from the lumen of the delivery sheath, the push assembly drives the limiting member to move along the first direction. Since the support structure that has not completely detached from the lumen of the delivery sheath is still in a retracted state, the push assembly can drive the support structure to move along the guidewire direction within the lumen of the delivery sheath through the pushing action of the limiting member, thereby adjusting the release position of the filter. After the filter is adjusted to the appropriate release position, the push assembly drives the support structure to move towards the target position within the lumen of the delivery sheath through the pushing action of the limiting member, thereby achieving precise release of the filter at the target position, reducing the risk of thrombus dislodgement or filter displacement, ensuring the stability of the filter's correct position within the blood vessel, and fully utilizing its thrombus-capturing function. Attached Figure Description

[0030] Figure 1This is an overall schematic diagram of the vena cava filter delivery system disclosed in this invention;

[0031] Figure 2 A schematic diagram of a vena cava filter delivery system, omitting the delivery sheath and suction tube;

[0032] Figure 3 A schematic diagram of multiple sets of support structures whose length increases along the first direction;

[0033] Figure 4 A cross-sectional view of the filter being housed in a retracted state within the delivery sheath;

[0034] Figure 5 This is a schematic diagram of the filter in its deployed state;

[0035] Figure 6 A flowchart of the control method for a vena cava filter delivery system. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0037] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “inner,” “outer,” “upper,” “lower,” “far,” “near,” “front,” and “back” are used only to indicate relative positional relationships; these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0038] The accompanying drawings in this disclosure are not drawn to scale, and the specific dimensions and quantity of each structure can be determined according to actual needs. The drawings described in this disclosure are only structural schematic diagrams.

[0039] It should be noted that "axis" refers to Figure 1The direction indicated by the axis Q of the central delivery sheath 10. "Radial" refers to the direction J passing through axis Q.

[0040] Pulmonary embolism (PE) and deep vein thrombosis (DVT) are collectively referred to as venous thromboembolism (VTE). A vena cava filter (VCF) is a filtration device designed to prevent pulmonary embolism caused by emboli dislodging from the superior and inferior vena cava systems.

[0041] Based on their duration of use and function, vena cava filters can be mainly classified into the following categories: Temporary filters, typically used for patients requiring short-term protection against thrombus dislodgement; Permanent filters, designed for long-term implantation and not to be removed, suitable for patients at lifelong high risk; and Retrievable filters, combining the advantages of temporary and permanent filters. These filters can be implanted when needed and removed surgically or through other medical means once the thrombosis risk decreases. This allows patients to benefit when the thrombosis risk is high, while avoiding the side effects of long-term implantation when the risk decreases.

[0042] However, in the existing vena cava filter delivery devices, if the filter's position deviates during the release process, it is usually impossible to adjust the filter's position again. This may result in the filter not being accurately released into the appropriate location in the inferior vena cava, thereby increasing the risk of thrombus dislodgement or filter displacement and reducing the success rate of the procedure.

[0043] The inferior vena cava filter delivery system 100 disclosed in this application, compared with the inferior vena cava filter delivery devices in the prior art, when the release position of the filter 40 is offset, before a set of support structures 42 near the distal end of the delivery sheath 10 unfolds, the system 100 uses a pushing component 30 to drive the support structures 42 to move along a first direction within the lumen of the delivery sheath 10 to adjust the release position of the filter 40. After the filter 40 is adjusted to a suitable release position, the pushing component 30 drives the support structures 42 to move along a second direction from the lumen of the delivery sheath 10 to the target position outside the lumen of the delivery sheath 10, so as to accurately release the filter 40 in the appropriate position in the inferior vena cava, reducing the risk of thrombus dislodgement or filter 40 displacement.

[0044] Please refer to Figures 1 to 5 A specific embodiment of a vena cava filter delivery system 100 is disclosed.

[0045] The vena cava filter delivery system 100 includes: a delivery sheath 10, a sealing assembly 20, a pushing assembly 30, and a filter 40; the sealing assembly 20 is disposed at the proximal end of the delivery sheath 10, the filter 40 is received within the lumen of the delivery sheath 10, the pushing assembly 30 extends continuously into the lumen of the sealing assembly 20 and the delivery sheath 10 and drives the filter 40 to move relative to the delivery sheath 10; a limiting member 31 is disposed at the distal end of the pushing assembly 30; the filter 40 is configured in multiple sets that are circumferentially equally spaced and whose length is along a first direction (e.g., ...). Figure 3 The support structure 42 increases in the direction indicated by the middle arrow X1; the support structure 42 is held in a retracted state between the delivery sheath 10 and the limiting member 31 radially J, and the retracted support structure 42 is pushed by the limiting member 31 along the first direction or in a second direction opposite to the first direction (i.e., Figure 4 (In the direction indicated by the middle arrow X2) it moves within the inner cavity of the delivery sheath 10.

[0046] The inferior vena cava filter delivery system 100 provided in the above embodiments of this application, during surgery, guide wire (not shown) is inserted into the target blood vessel to provide a guiding path for the delivery filter 40. After the air inside the delivery sheath 10 is purged by the sealing assembly 20, the delivery sheath 10 is guided along the guide wire to the target position in the inferior vena cava. At the same time, the filter 40 remains in a contracted state within the lumen of the delivery sheath 10. After reaching the target position, the pushing assembly 30 is controlled to move the limiting member 31 in the second direction, so that the pushing action of the limiting member 31 drives the contracted support structure 42 (e.g., Figure 4 The support structure 42 shown moves along the second direction from inside the delivery sheath 10 to outside the delivery sheath 10. By continuously pushing the limiting member 31 along the second direction, the filter 40 will gradually move to the target position. Multiple sets of support structures 42 (i.e., Figure 5 The support structures 42a, 42b, and 42c shown in the diagram sequentially detach from the inner cavity of the delivery sheath 10 along the second direction. The support structure 42, having completely detached from the inner cavity of the delivery sheath 10, can switch from a retracted state to an extended state (e.g., ...). Figure 5 The support structure 42 shown in the figure.

[0047] If the release position of the filter 40 shifts during its gradual movement toward the target position, a set of support structures 42 (i.e., near the distal end of the delivery sheath 10) will be affected. Figure 5Before the support structure 42a) shown is completely detached from the inner lumen of the delivery sheath 10, the control push component 30 drives the limiting member 31 to move along the first direction. Since the support structure 42a, which is not completely detached from the inner lumen of the delivery sheath 10, is still in a retracted state, the push component 30 can drive the support structure 42a to move along the first direction in the inner lumen of the delivery sheath 10 through the pushing action of the limiting member 31, so as to adjust the release position of the filter 40. After the filter 40 is adjusted to the appropriate release position, the control push component 30 drives the support structure 42a to move towards the target position in the inner lumen of the delivery sheath 10 through the pushing action of the limiting member 31, so as to accurately release the filter 40 in the target position, thereby reducing the risk of thrombus dislodgement or filter 40 displacement, ensuring the stability of the correct position of the filter 40 in the blood vessel, and giving full play to its function of capturing thrombi.

[0048] In some examples, the air inside the delivery sheath 10 is purged by the sealing assembly 20 to ensure that there is no air inside the delivery sheath 10, thereby preventing air from entering the blood vessel during delivery and reducing surgical risks.

[0049] In some examples, the radial J-direction abutment between the limiting member 31 and the delivery sheath 10 against the support structure 42 causes the outer surface of the limiting member 31 to contact the inner surface of the support structure 42, and the outer surface of the support structure 42 to contact the inner surface of the delivery sheath 10, thereby generating friction to restrict the position of the filter 40 within the inner cavity of the delivery sheath 10. This prevents the filter 40 from detaching from the inner cavity of the delivery sheath 10 before reaching the target position, avoiding accidental release. Furthermore, the friction between the limiting member 31 and the support structure 42 allows the limiting member 31 to push the support structure 42 as it moves along the first or second direction, thus driving the support structure 42 to move synchronously.

[0050] In some examples, as the filter 40 moves from the lumen of the delivery sheath 10 to the target location, multiple sets of support structures 42 sequentially detach from the lumen of the delivery sheath 10, and after completely detaching, sequentially switch from a retracted state to an extended state. The sequential deployment of the multiple support structures 42, rather than all at once, reduces the impact on the blood vessel caused by a single, complete deployment. This sequential deployment evenly distributes the pressure applied to the blood vessel, preventing damage. Furthermore, during the sequential deployment of the multiple support structures 42, the set of support structures 42 that detaches completely from the lumen of the delivery sheath 10 first provides stable support to the subsequent support structures 42 detaching from the lumen of the delivery sheath 10 by abutting against the blood vessel wall, thus ensuring that the filter 40 can be smoothly and accurately deployed and released at the target location.

[0051] In some examples, the limiting member 31 is made of a flexible material, such as silicone, polyurethane (PU), or thermoplastic elastomer (TPE), and this disclosure is not limited thereto. This allows the limiting member 31 to flexibly fix the support structure 42 of the filter 40 and provide support force and elastic cushioning. During the conveying of the support structure 42, the limiting member 31 and the support structure 42 generate a moderate frictional force, which can stabilize the retracted state of the support structure 42 and also facilitate the smooth sliding of the support structure 42 within the inner cavity of the conveying sheath 10 when the pushing component 30 applies force.

[0052] In some examples, the parameter Figures 1 to 4 As shown, the filter 40 includes a head end 41 that engages with the opening of the delivery sheath 10, and multiple sets of support structures 42 extending from the end of the head end 41 along a first direction. By engaging the head end 41 with the opening of the delivery sheath 10, the filter 40 is kept stable within the inner cavity of the delivery sheath 10 during delivery, further preventing the filter 40 from dislodging from the inner cavity of the delivery sheath 10 before reaching the target position, thus avoiding accidental release. As the pushing component 30 drives the limiting member 31 to move along the second direction, the pushing action of the limiting member 31 drives the support structure 42 in the retracted state to move along the second direction within the inner cavity of the delivery sheath 10, causing the head end 41, which is engaged with the port of the delivery sheath 10, to disengage from the inner cavity of the delivery sheath 10. As the filter 40 gradually moves to the target position, multiple sets of support structures 42 disengage from the inner cavity of the delivery sheath 10 in sequence and switch from the retracted state to the unfolded state in sequence. After the filter 40 is released at the target position, multiple sets of support structures 42 unfold and form a stable umbrella-shaped structure to maintain the stability of the filter 40 in the blood vessel and effectively capture and prevent thrombi from entering the lungs.

[0053] In some examples, the parameter Figures 3 to 5As shown, the support structure 42 includes multiple first support arms 421, second support arms 422, and third support arms 423 whose lengths increase along a first direction; the length of the first support arm 421 is less than the length of the second support arm 422, and the length of the second support arm 422 is less than the length of the third support arm 423. The lengths of the first support arms 421, second support arms 422, and third support arms 423 gradually increase, so that each set of support arms (i.e., multiple first support arms 421, second support arms 422, and third support arms 423 whose lengths increase along the first direction) can gradually apply a supporting force to the inner wall of the blood vessel when deployed sequentially, so that the filter 40 can be stably deployed and maintained in position within the inferior vena cava. Furthermore, by gradually increasing the lengths of the first support arm 421, the second support arm 422, and the third support arm 423, the filter 40 can adapt to different blood vessel diameters. The shorter first support arm 421 is located near the proximal end of the filter 40 to accommodate different blood vessel diameters and shapes in different patients, while the longer second and third support arms 422 and 423 are located at the distal end of the filter 40 to accommodate larger blood vessel diameters. This provides stable support for the filter 40 when deployed, preventing displacement or instability within the blood vessel. The gradual deployment of the first support arm 421, the second support arm 422, and the third support arm 423 enhances the fixation ability of the filter 40, ensuring that the filter 40 can remain stably in the target position for a long time.

[0054] In some examples, the parameter Figure 4 and Figure 5 As shown, the tip 41 has a conical structure on the outside and forms a through guidewire lumen (not shown). The center of the tip 41 is hollowed out to form a hook-shaped structure. The tip 41 is constructed with a protrusion 411 that fits into the opening of the delivery sheath 10. The conical structure on the outside of the tip 41 helps to smoothly guide the filter 40 through the blood vessel during delivery, thereby reducing the resistance of the delivery sheath 10 during insertion. The guidewire lumen provides an insertion channel for the guidewire, allowing the guidewire to pass through the tip 41 and guide the filter 40 to move accurately to the target position, ensuring the precise positioning of the filter 40. The hook-shaped structure is used to retrieve the filter 40. The protrusion 411 allows the tip 41 to fit into the opening of the delivery sheath 10, preventing accidental loosening of the filter 40 during delivery and ensuring that the filter 40 remains stably closed in the inner cavity of the delivery sheath 10.

[0055] In some examples, the parameter Figure 4 and Figure 5As shown, the limiting member 31 at least partially radially abuts against the third support arm 423 in its retracted state and extends toward the first support arm 421. By abutting the retracted third support arm 423 radially, the limiting member 31 ensures the stability of the filter 40 during delivery. The abutting action of the limiting member 31 also secures the third support arm 423 within the inner cavity of the delivery sheath 10, preventing accidental unfolding or displacement during delivery. This ensures the filter 40 can smoothly pass through the blood vessel and reach the target position. Furthermore, the friction between the limiting member 31 and the third support arm 423 drives the filter 40 to move along the second or first direction within the inner cavity of the delivery sheath 10. In some examples, the limiting member 31 may extend along the second direction to the second support arm 422, or even to the first support arm 421, so that the limiting member 31 radially abuts against the retracted first support arm 421, second support arm 422, and third support arm 423. This allows for effective control of the gradual release of the first support arm 421, the second support arm 422, and the third support arm 423, ensuring that the filter 40 unfolds smoothly and precisely.

[0056] In some examples, the parameter Figures 2 to 4 As shown, the delivery assembly 30 includes: an inner sheath 32 extending continuously into the lumens of the sealing assembly 20 and the delivery sheath 10; a limiting member 31 sleeved on the distal outer side of the inner sheath 32; and a handle 33 disposed at one end of the inner sheath 32 extending out of the sealing assembly 20. The inner sheath 32 extends continuously into the lumens of the sealing assembly 20 and the delivery sheath 10, and the lumens of the inner sheath 32 are aligned with and communicate with the guidewire lumen in the tip 41, providing an insertion channel for the guidewire. The movement of the inner sheath 32 and the limiting member 31 within the lumens of the delivery sheath 10 is controlled by the handle 33 to adjust the position of the filter 40 in real time, and the inner sheath 32 guides the filter 40, keeping it stable during delivery and enabling the filter 40 to be accurately and smoothly deployed to the target location in the inferior vena cava.

[0057] In some examples, the parameter Figures 2 to 4 As shown, the inner sheath 32 is radially recessed to form a connecting tube section 321 with a limiting member 31. The distal end of the connecting tube section 321 is connected to the head end 41. The outer diameter of the connecting tube section 321 is smaller than the outer diameter of the inner sheath 32, so that the inner cavity of the delivery sheath 10 can accommodate the limiting member 31 and the support structure 42 in the retracted state, thereby reducing friction and resistance during the release of the filter 40 and ensuring that the filter 40 can be released smoothly and gradually unfolded.

[0058] In some examples, the parameter Figure 5As shown, the first support arm 421 includes: a first support portion 4211 and a second support portion 4212 that extend continuously outward relative to the axis of the filter 40, and a third support portion 4213 that connects to the second support portion 4212 and extends continuously inward relative to the axis of the filter 40.

[0059] The first support portion 4211 initially supports the first support arm 421 during its deployment, providing initial external force support. The second support portion 4212 further expands to provide greater support. Together, the first and second support portions 4211 and 4212 support the first support arm 421 during deployment, and the second support portion 4212 distributes the support force, ensuring uniform pressure on the blood vessel during deployment. This prevents excessive local pressure on the blood vessel when the filter 40 expands within the target area, avoiding damage. The third support portion 4213 extends inward to create a centripetal support force within the filter 40, balancing the outward support forces of the first and second support portions 4211 and 4212. This prevents deformation of the first support arm 421 due to excessive outward support during deployment, ensuring the overall rigidity and stability of the filter 40.

[0060] In some examples, the parameter Figure 5 As shown, the second support arm 422 has an overall arc-shaped structure, and its free end is equipped with a barb 4221 that bends radially outward for anchoring on the inner wall of the blood vessel. The arc-shaped structure of the second support arm 422 allows it to adapt to the shape of the blood vessel when deployed, ensuring even pressure distribution on the vessel wall and preventing excessive local pressure, thus reducing the risk of vascular damage. Furthermore, the second support arm 422 provides uniform support for the filter 40 when deployed, ensuring stable deployment at the target position and providing stable support for the subsequent release of the third support arm 423. After deployment, the barb 4221 firmly contacts the inner wall of the blood vessel, preventing the filter 40 from moving with the blood flow and ensuring it remains stably in the target position.

[0061] In some examples, the parameter Figure 5As shown, the third support arm 423 has a linear overall profile, and its free end extends along the first direction to form an anchor 4231 for anchoring on the inner wall of the blood vessel. The linear structure of the third support arm 423 helps provide more stable linear support for the filter 40 within the blood vessel, enabling the filter 40 to provide solid support when deployed. Furthermore, the third support arm 423 can deploy quickly and stably, preventing excessive disturbance to the filter 40 and keeping it in the target position, ensuring the stability of the filter 40 structure. The anchor 4231 penetrates the blood vessel wall, ensuring the filter 40 is firmly anchored on the inner wall of the blood vessel, preventing displacement or detachment of the filter 40 under the influence of blood flow.

[0062] In some examples, the parameter Figure 5 As shown, the angle at which the first support portion 4211 of the first support arm 421 extends outward from the end of the head 41 is greater than the angle at which the second support arm 422 extends outward from the end of the head 41. The larger angle at which the first support portion 4211 of the first support arm 421 extends outward from the head 41 provides stronger initial support during the deployment of the filter 40, facilitating the rapid adaptation of the filter 40 to the space within the blood vessel and ensuring sufficient support during the initial deployment phase, enabling the filter 40 to be stably positioned at the target location within the blood vessel.

[0063] In some examples, the parameter Figure 1 As shown, the sealing assembly 20 includes: a multi-channel valve tube 21 and a suction tube 22. The side of the multi-channel valve tube 21 is configured with a side tube 211 communicating with the suction tube 22, and a seal (not shown) disposed at the proximal end of the multi-channel valve tube 21. An inner sheath tube 32 extends through the multi-channel valve tube 21 in a second direction and extends to the delivery sheath tube 10. The seal is used to seal the connection between the inner sheath tube 32 and the proximal end of the multi-channel valve tube 21. A vacuum device (not shown) is externally connected to the suction tube 22, enabling the suction tube 22 to suction and evacuate air from the multi-channel valve tube 21 and the delivery sheath tube 10, clearing air or impurities from inside the vena cava filter delivery system 100, ensuring smooth delivery of the filter 40. The seal, disposed at the proximal end of the multi-channel valve tube 21, seals the connection between the inner sheath tube 32 and the multi-channel valve tube 21 to prevent leakage of blood, liquid, or gas, maintaining the sealing integrity of the sealing assembly 20 and preventing risks caused by gas or blood leakage. In some examples, the seal may be configured as a sealing nut to lock the position of the inner sheath 32 and maintain the seal of the sealing assembly 20. During the delivery of the filter 40 through the inner sheath 32, the sealing nut may be loosened appropriately, allowing the inner sheath 32 to move relative to the delivery sheath 10 to adjust the release position of the filter 40.

[0064] Based on the same inventive concept, this embodiment also discloses a control method for a vena cava filter delivery system 100, see reference. Figure 6As shown, the surgical procedure assisted by the above-disclosed vena cava filter delivery system 100 includes the following steps:

[0065] S1. The air inside the delivery sheath 10 is vented through the sealing assembly 20; S2. The delivery sheath 10 is guided along the guidewire to the target position in the inferior vena cava; S3. The pushing assembly 30 drives the limiting member 31 to move along the second direction, i.e., the guidewire direction, and the pushing action of the limiting member 31 moves the folded support structure 42 along the second direction from inside the delivery sheath 10 to outside the delivery sheath 10; S4. After the filter 40 moves from inside the delivery sheath 10 to the target position outside the delivery sheath 10, the support structure 42 switches from the folded state to the unfolded state.

[0066] Specifically, during the procedure, a guidewire (not shown) is inserted into the target blood vessel to provide a guiding path for the delivery filter 40. The second direction is the direction of the guidewire. After the air inside the delivery sheath 10 is purged by the sealing assembly 20, the delivery sheath 10 is guided along the guidewire to the target location in the inferior vena cava and released directly along the guidewire. Simultaneously, the filter 40 remains in a retracted state within the lumen of the delivery sheath 10. Upon reaching the target location, the pushing assembly 30 is controlled to move the limiting member 31 along the second direction. The pushing action of the limiting member 31 then drives the retracted support structure 42 (e.g., Figure 4 The support structure 42 shown moves along the second direction from inside the delivery sheath 10 to outside the delivery sheath 10. By continuously pushing the limiting member 31 along the second direction, the filter 40 will gradually move to the target position. Multiple sets of support structures 42 (i.e., Figure 5 The support structures 42a, 42b and 42c shown in the diagram sequentially detach from the inner cavity of the delivery sheath 10 along the second direction. The support structure 42, which is completely detached from the inner cavity of the delivery sheath 10, can be switched from a retracted state to an extended state.

[0067] In some examples, if the release position of the filter 40 is deviated, the push assembly 30 moves the support structure 42 along a first direction within the lumen of the delivery sheath 10 before the set of support structures 42 near the distal end of the delivery sheath 10 unfolds, in order to adjust the release position of the filter 40. After the filter 40 is adjusted to the appropriate release position, the push assembly 30 moves the support structure 42 along a second direction from the lumen of the delivery sheath 10 to the target position outside the lumen of the delivery sheath 10, thereby reducing the risk of thrombus dislodgement or filter 40 displacement, ensuring the stability of the correct position of the filter 40 in the blood vessel, and fully utilizing its function of capturing thrombi.

[0068] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A vena cava filter delivery system, characterized in that, include: Delivery sheath, sealing assembly, push assembly, and filter; The sealing assembly is disposed at the proximal end of the delivery sheath, the filter is housed in the inner cavity of the delivery sheath, and the pushing assembly extends continuously into the inner cavity of the sealing assembly and the delivery sheath and drives the filter to move within the delivery sheath. The remote end of the push component is configured with a limiting device; The filter is constructed with multiple sets of support structures that are equally spaced along the circumference and whose length increases along the first direction. The filter includes: a head end, and a plurality of support structures extending from the end of the head end along the first direction; the support structure includes: a plurality of first support arms, second support arms and third support arms whose lengths increase along the first direction; The pushing component includes: an inner sheath tube, the inner sheath tube being radially recessed to form a connecting tube segment on which the limiting member is disposed, the distal end of the connecting tube segment being connected to the head end, and the limiting member being sleeved on the outside of the connecting tube segment; the limiting member is made of a flexible material so that the limiting member can flexibly fix the support structure of the filter and provide support force and elastic buffer. The support structure is held in a retracted state between the delivery sheath and the limiting member radially. The limiting member and the inner wall of the delivery sheath together form a radial abutment against the support structure in the retracted state, so that the outer surface of the limiting member contacts the inner surface of the support structure, and the outer surface of the support structure contacts the inner surface of the delivery sheath, thereby generating friction. The limiting member abuts the first support arm, the second support arm, and the third support arm in the retracted state radially. The collapsible support structure is moved within the inner cavity of the delivery sheath along the first direction or in a second direction opposite to the first direction by the pushing action of the limiting member; before a set of support structures near the distal end of the delivery sheath completely detaches from the inner cavity of the delivery sheath, the support structures that are not completely detached remain in a collapsible state within the inner cavity of the delivery sheath, and the pushing component drives the collapsible support structure to move within the inner cavity of the delivery sheath along the first direction or the second direction by the pushing action of the limiting member, so as to adjust the release position of the filter.

2. The vena cava filter delivery system according to claim 1, characterized in that, The head end engages with the opening of the delivery sheath.

3. The vena cava filter delivery system according to claim 2, characterized in that, The head end has a conical structure on the outside and a through guide wire cavity. The center of the head end is hollowed out to form a hook-shaped structure. The head end is constructed to have a protrusion that fits into the opening of the delivery sheath.

4. The vena cava filter delivery system according to claim 1, characterized in that, The inner sheath extends continuously into the inner cavity of the sealing assembly and the delivery sheath, and a handle is provided at one end of the inner sheath extending out of the sealing assembly.

5. The vena cava filter delivery system according to claim 1, characterized in that, The first support arm includes: a first support portion and a second support portion extending continuously outward relative to the axis of the filter, and a third support portion connecting the second support portion and sealing the assembly extending continuously inward relative to the axis of the filter.

6. The vena cava filter delivery system according to claim 1, characterized in that, The second support arm has an overall arc-shaped structure, and the free end of the second support arm is provided with barbs that bend radially outward for anchoring on the inner wall of the blood vessel.

7. The vena cava filter delivery system according to claim 1, characterized in that, The overall outline of the third support arm is a straight structure, and the free end of the third support arm extends along the first direction to form an anchor thorn for anchoring on the inner wall of the blood vessel.

8. The vena cava filter delivery system according to claim 5, characterized in that, The angle at which the first support portion of the first support arm extends outward from the end of the head is greater than the angle at which the second support arm extends outward from the end of the head.

9. The vena cava filter delivery system according to claim 4, characterized in that, The sealing assembly includes: a multi-channel valve tube and a suction tube, the side of the multi-channel valve tube being configured to communicate with the suction tube, and a seal disposed at the proximal end of the multi-channel valve tube; The inner sheath extends through the multi-channel valve tube along the second direction and extends to the delivery sheath tube, and the seal is used to seal the connection between the inner sheath tube and the proximal end of the multi-channel valve tube.

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